sys/netinet6/udp6_usrreq.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * Copyright (c) 2010-2011 Juniper Networks, Inc.
   4  * Copyright (c) 2014 Kevin Lo
   5  * All rights reserved.
   6  *
   7  * Portions of this software were developed by Robert N. M. Watson under
   8  * contract to Juniper Networks, Inc.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the project nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      $KAME: udp6_usrreq.c,v 1.27 2001/05/21 05:45:10 jinmei Exp $
  35  *      $KAME: udp6_output.c,v 1.31 2001/05/21 16:39:15 jinmei Exp $
  36  */
  37
  38 /*-
  39  * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
  40  *      The Regents of the University of California.
  41  * All rights reserved.
  42  *
  43  * Redistribution and use in source and binary forms, with or without
  44  * modification, are permitted provided that the following conditions
  45  * are met:
  46  * 1. Redistributions of source code must retain the above copyright
  47  *    notice, this list of conditions and the following disclaimer.
  48  * 2. Redistributions in binary form must reproduce the above copyright
  49  *    notice, this list of conditions and the following disclaimer in the
  50  *    documentation and/or other materials provided with the distribution.
  51  * 4. Neither the name of the University nor the names of its contributors
  52  *    may be used to endorse or promote products derived from this software
  53  *    without specific prior written permission.
  54  *
  55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  65  * SUCH DAMAGE.
  66  *
  67  *      @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
  68  */
  69
  70 #include <sys/cdefs.h>
  71 __FBSDID("$FreeBSD$");
  72
  73 #include "opt_inet.h"
  74 #include "opt_inet6.h"
  75 #include "opt_ipfw.h"
  76 #include "opt_ipsec.h"
  77 #include "opt_kdtrace.h"
  78
  79 #include <sys/param.h>
  80 #include <sys/jail.h>
  81 #include <sys/kernel.h>
  82 #include <sys/lock.h>
  83 #include <sys/mbuf.h>
  84 #include <sys/priv.h>
  85 #include <sys/proc.h>
  86 #include <sys/protosw.h>
  87 #include <sys/sdt.h>
  88 #include <sys/signalvar.h>
  89 #include <sys/socket.h>
  90 #include <sys/socketvar.h>
  91 #include <sys/sx.h>
  92 #include <sys/sysctl.h>
  93 #include <sys/syslog.h>
  94 #include <sys/systm.h>
  95
  96 #include <net/if.h>
  97 #include <net/if_types.h>
  98 #include <net/route.h>
  99
 100 #include <netinet/in.h>
 101 #include <netinet/in_kdtrace.h>
 102 #include <netinet/in_pcb.h>
 103 #include <netinet/in_systm.h>
 104 #include <netinet/in_var.h>
 105 #include <netinet/ip.h>
 106 #include <netinet/ip_icmp.h>
 107 #include <netinet/ip6.h>
 108 #include <netinet/icmp_var.h>
 109 #include <netinet/icmp6.h>
 110 #include <netinet/ip_var.h>
 111 #include <netinet/udp.h>
 112 #include <netinet/udp_var.h>
 113 #include <netinet/udplite.h>
 114
 115 #include <netinet6/ip6protosw.h>
 116 #include <netinet6/ip6_var.h>
 117 #include <netinet6/in6_pcb.h>
 118 #include <netinet6/udp6_var.h>
 119 #include <netinet6/scope6_var.h>
 120
 121 #ifdef IPSEC
 122 #include <netipsec/ipsec.h>
 123 #include <netipsec/ipsec6.h>
 124 #endif /* IPSEC */
 125
 126 #include <security/mac/mac_framework.h>
 127
 128 /*
 129  * UDP protocol implementation.
 130  * Per RFC 768, August, 1980.
 131  */
 132
 133 extern struct protosw   inetsw[];
 134 static void             udp6_detach(struct socket *so);
 135
 136 static void
 137 udp6_append(struct inpcb *inp, struct mbuf *n, int off,
 138     struct sockaddr_in6 *fromsa)
 139 {
 140         struct socket *so;
 141         struct mbuf *opts;
 142         struct udpcb *up;
 143
 144         INP_LOCK_ASSERT(inp);
 145
 146         /*
 147          * Engage the tunneling protocol.
 148          */
 149         up = intoudpcb(inp);
 150         if (up->u_tun_func != NULL) {
 151                 (*up->u_tun_func)(n, off, inp);
 152                 return;
 153         }
 154 #ifdef IPSEC
 155         /* Check AH/ESP integrity. */
 156         if (ipsec6_in_reject(n, inp)) {
 157                 m_freem(n);
 158                 IPSEC6STAT_INC(ips_in_polvio);
 159                 return;
 160         }
 161 #endif /* IPSEC */
 162 #ifdef MAC
 163         if (mac_inpcb_check_deliver(inp, n) != 0) {
 164                 m_freem(n);
 165                 return;
 166         }
 167 #endif
 168         opts = NULL;
 169         if (inp->inp_flags & INP_CONTROLOPTS ||
 170             inp->inp_socket->so_options & SO_TIMESTAMP)
 171                 ip6_savecontrol(inp, n, &opts);
 172         m_adj(n, off + sizeof(struct udphdr));
 173
 174         so = inp->inp_socket;
 175         SOCKBUF_LOCK(&so->so_rcv);
 176         if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)fromsa, n,
 177             opts) == 0) {
 178                 SOCKBUF_UNLOCK(&so->so_rcv);
 179                 m_freem(n);
 180                 if (opts)
 181                         m_freem(opts);
 182                 UDPSTAT_INC(udps_fullsock);
 183         } else
 184                 sorwakeup_locked(so);
 185 }
 186
 187 int
 188 udp6_input(struct mbuf **mp, int *offp, int proto)
 189 {
 190         struct mbuf *m = *mp;
 191         struct ifnet *ifp;
 192         struct ip6_hdr *ip6;
 193         struct udphdr *uh;
 194         struct inpcb *inp;
 195         struct inpcbinfo *pcbinfo;
 196         struct udpcb *up;
 197         int off = *offp;
 198         int cscov_partial;
 199         int plen, ulen;
 200         struct sockaddr_in6 fromsa;
 201         struct m_tag *fwd_tag;
 202         uint16_t uh_sum;
 203         uint8_t nxt;
 204
 205         ifp = m->m_pkthdr.rcvif;
 206         ip6 = mtod(m, struct ip6_hdr *);
 207
 208         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 209                 /* XXX send icmp6 host/port unreach? */
 210                 m_freem(m);
 211                 return (IPPROTO_DONE);
 212         }
 213
 214 #ifndef PULLDOWN_TEST
 215         IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
 216         ip6 = mtod(m, struct ip6_hdr *);
 217         uh = (struct udphdr *)((caddr_t)ip6 + off);
 218 #else
 219         IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
 220         if (!uh)
 221                 return (IPPROTO_DONE);
 222 #endif
 223
 224         UDPSTAT_INC(udps_ipackets);
 225
 226         /*
 227          * Destination port of 0 is illegal, based on RFC768.
 228          */
 229         if (uh->uh_dport == 0)
 230                 goto badunlocked;
 231
 232         plen = ntohs(ip6->ip6_plen) - off + sizeof(*ip6);
 233         ulen = ntohs((u_short)uh->uh_ulen);
 234
 235         nxt = ip6->ip6_nxt;
 236         cscov_partial = (nxt == IPPROTO_UDPLITE) ? 1 : 0;
 237         if (nxt == IPPROTO_UDPLITE) {
 238                 /* Zero means checksum over the complete packet. */
 239                 if (ulen == 0)
 240                         ulen = plen;
 241                 if (ulen == plen)
 242                         cscov_partial = 0;
 243                 if ((ulen < sizeof(struct udphdr)) || (ulen > plen)) {
 244                         /* XXX: What is the right UDPLite MIB counter? */
 245                         goto badunlocked;
 246                 }
 247                 if (uh->uh_sum == 0) {
 248                         /* XXX: What is the right UDPLite MIB counter? */
 249                         goto badunlocked;
 250                 }
 251         } else {
 252                 if ((ulen < sizeof(struct udphdr)) || (plen != ulen)) {
 253                         UDPSTAT_INC(udps_badlen);
 254                         goto badunlocked;
 255                 }
 256                 if (uh->uh_sum == 0) {
 257                         UDPSTAT_INC(udps_nosum);
 258                         goto badunlocked;
 259                 }
 260         }
 261
 262         if ((m->m_pkthdr.csum_flags & CSUM_DATA_VALID_IPV6) &&
 263             !cscov_partial) {
 264                 if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
 265                         uh_sum = m->m_pkthdr.csum_data;
 266                 else
 267                         uh_sum = in6_cksum_pseudo(ip6, ulen, nxt,
 268                             m->m_pkthdr.csum_data);
 269                 uh_sum ^= 0xffff;
 270         } else
 271                 uh_sum = in6_cksum_partial(m, nxt, off, plen, ulen);
 272
 273         if (uh_sum != 0) {
 274                 UDPSTAT_INC(udps_badsum);
 275                 goto badunlocked;
 276         }
 277
 278         /*
 279          * Construct sockaddr format source address.
 280          */
 281         init_sin6(&fromsa, m);
 282         fromsa.sin6_port = uh->uh_sport;
 283
 284         pcbinfo = get_inpcbinfo(nxt);
 285         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 286                 struct inpcb *last;
 287                 struct inpcbhead *pcblist;
 288                 struct ip6_moptions *imo;
 289
 290                 INP_INFO_RLOCK(pcbinfo);
 291                 /*
 292                  * In the event that laddr should be set to the link-local
 293                  * address (this happens in RIPng), the multicast address
 294                  * specified in the received packet will not match laddr.  To
 295                  * handle this situation, matching is relaxed if the
 296                  * receiving interface is the same as one specified in the
 297                  * socket and if the destination multicast address matches
 298                  * one of the multicast groups specified in the socket.
 299                  */
 300
 301                 /*
 302                  * KAME note: traditionally we dropped udpiphdr from mbuf
 303                  * here.  We need udphdr for IPsec processing so we do that
 304                  * later.
 305                  */
 306                 pcblist = get_pcblist(nxt);
 307                 last = NULL;
 308                 LIST_FOREACH(inp, pcblist, inp_list) {
 309                         if ((inp->inp_vflag & INP_IPV6) == 0)
 310                                 continue;
 311                         if (inp->inp_lport != uh->uh_dport)
 312                                 continue;
 313                         if (inp->inp_fport != 0 &&
 314                             inp->inp_fport != uh->uh_sport)
 315                                 continue;
 316                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)) {
 317                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr,
 318                                                         &ip6->ip6_dst))
 319                                         continue;
 320                         }
 321                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 322                                 if (!IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr,
 323                                                         &ip6->ip6_src) ||
 324                                     inp->inp_fport != uh->uh_sport)
 325                                         continue;
 326                         }
 327
 328                         /*
 329                          * XXXRW: Because we weren't holding either the inpcb
 330                          * or the hash lock when we checked for a match
 331                          * before, we should probably recheck now that the
 332                          * inpcb lock is (supposed to be) held.
 333                          */
 334
 335                         /*
 336                          * Handle socket delivery policy for any-source
 337                          * and source-specific multicast. [RFC3678]
 338                          */
 339                         imo = inp->in6p_moptions;
 340                         if (imo && IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 341                                 struct sockaddr_in6      mcaddr;
 342                                 int                      blocked;
 343
 344                                 INP_RLOCK(inp);
 345
 346                                 bzero(&mcaddr, sizeof(struct sockaddr_in6));
 347                                 mcaddr.sin6_len = sizeof(struct sockaddr_in6);
 348                                 mcaddr.sin6_family = AF_INET6;
 349                                 mcaddr.sin6_addr = ip6->ip6_dst;
 350
 351                                 blocked = im6o_mc_filter(imo, ifp,
 352                                         (struct sockaddr *)&mcaddr,
 353                                         (struct sockaddr *)&fromsa);
 354                                 if (blocked != MCAST_PASS) {
 355                                         if (blocked == MCAST_NOTGMEMBER)
 356                                                 IP6STAT_INC(ip6s_notmember);
 357                                         if (blocked == MCAST_NOTSMEMBER ||
 358                                             blocked == MCAST_MUTED)
 359                                                 UDPSTAT_INC(udps_filtermcast);
 360                                         INP_RUNLOCK(inp); /* XXX */
 361                                         continue;
 362                                 }
 363
 364                                 INP_RUNLOCK(inp);
 365                         }
 366                         if (last != NULL) {
 367                                 struct mbuf *n;
 368
 369                                 if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
 370                                         INP_RLOCK(last);
 371                                         UDP_PROBE(receive, NULL, last, ip6,
 372                                             last, uh);
 373                                         udp6_append(last, n, off, &fromsa);
 374                                         INP_RUNLOCK(last);
 375                                 }
 376                         }
 377                         last = inp;
 378                         /*
 379                          * Don't look for additional matches if this one does
 380                          * not have either the SO_REUSEPORT or SO_REUSEADDR
 381                          * socket options set.  This heuristic avoids
 382                          * searching through all pcbs in the common case of a
 383                          * non-shared port.  It assumes that an application
 384                          * will never clear these options after setting them.
 385                          */
 386                         if ((last->inp_socket->so_options &
 387                              (SO_REUSEPORT|SO_REUSEADDR)) == 0)
 388                                 break;
 389                 }
 390
 391                 if (last == NULL) {
 392                         /*
 393                          * No matching pcb found; discard datagram.  (No need
 394                          * to send an ICMP Port Unreachable for a broadcast
 395                          * or multicast datgram.)
 396                          */
 397                         UDPSTAT_INC(udps_noport);
 398                         UDPSTAT_INC(udps_noportmcast);
 399                         goto badheadlocked;
 400                 }
 401                 INP_RLOCK(last);
 402                 INP_INFO_RUNLOCK(pcbinfo);
 403                 UDP_PROBE(receive, NULL, last, ip6, last, uh);
 404                 udp6_append(last, m, off, &fromsa);
 405                 INP_RUNLOCK(last);
 406                 return (IPPROTO_DONE);
 407         }
 408         /*
 409          * Locate pcb for datagram.
 410          */
 411
 412         /*
 413          * Grab info from PACKET_TAG_IPFORWARD tag prepended to the chain.
 414          */
 415         if ((m->m_flags & M_IP6_NEXTHOP) &&
 416             (fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL)) != NULL) {
 417                 struct sockaddr_in6 *next_hop6;
 418
 419                 next_hop6 = (struct sockaddr_in6 *)(fwd_tag + 1);
 420
 421                 /*
 422                  * Transparently forwarded. Pretend to be the destination.
 423                  * Already got one like this?
 424                  */
 425                 inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
 426                     uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 427                     INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif, m);
 428                 if (!inp) {
 429                         /*
 430                          * It's new.  Try to find the ambushing socket.
 431                          * Because we've rewritten the destination address,
 432                          * any hardware-generated hash is ignored.
 433                          */
 434                         inp = in6_pcblookup(pcbinfo, &ip6->ip6_src,
 435                             uh->uh_sport, &next_hop6->sin6_addr,
 436                             next_hop6->sin6_port ? htons(next_hop6->sin6_port) :
 437                             uh->uh_dport, INPLOOKUP_WILDCARD |
 438                             INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif);
 439                 }
 440                 /* Remove the tag from the packet. We don't need it anymore. */
 441                 m_tag_delete(m, fwd_tag);
 442                 m->m_flags &= ~M_IP6_NEXTHOP;
 443         } else
 444                 inp = in6_pcblookup_mbuf(pcbinfo, &ip6->ip6_src,
 445                     uh->uh_sport, &ip6->ip6_dst, uh->uh_dport,
 446                     INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB,
 447                     m->m_pkthdr.rcvif, m);
 448         if (inp == NULL) {
 449                 if (udp_log_in_vain) {
 450                         char ip6bufs[INET6_ADDRSTRLEN];
 451                         char ip6bufd[INET6_ADDRSTRLEN];
 452
 453                         log(LOG_INFO,
 454                             "Connection attempt to UDP [%s]:%d from [%s]:%d\n",
 455                             ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 456                             ntohs(uh->uh_dport),
 457                             ip6_sprintf(ip6bufs, &ip6->ip6_src),
 458                             ntohs(uh->uh_sport));
 459                 }
 460                 UDPSTAT_INC(udps_noport);
 461                 if (m->m_flags & M_MCAST) {
 462                         printf("UDP6: M_MCAST is set in a unicast packet.\n");
 463                         UDPSTAT_INC(udps_noportmcast);
 464                         goto badunlocked;
 465                 }
 466                 if (V_udp_blackhole)
 467                         goto badunlocked;
 468                 if (badport_bandlim(BANDLIM_ICMP6_UNREACH) < 0)
 469                         goto badunlocked;
 470                 icmp6_error(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_NOPORT, 0);
 471                 return (IPPROTO_DONE);
 472         }
 473         INP_RLOCK_ASSERT(inp);
 474         up = intoudpcb(inp);
 475         if (cscov_partial) {
 476                 if (up->u_rxcslen == 0 || up->u_rxcslen > ulen) {
 477                         INP_RUNLOCK(inp);
 478                         m_freem(m);
 479                         return (IPPROTO_DONE);
 480                 }
 481         }
 482         UDP_PROBE(receive, NULL, inp, ip6, inp, uh);
 483         udp6_append(inp, m, off, &fromsa);
 484         INP_RUNLOCK(inp);
 485         return (IPPROTO_DONE);
 486
 487 badheadlocked:
 488         INP_INFO_RUNLOCK(pcbinfo);
 489 badunlocked:
 490         if (m)
 491                 m_freem(m);
 492         return (IPPROTO_DONE);
 493 }
 494
 495 static void
 496 udp6_common_ctlinput(int cmd, struct sockaddr *sa, void *d,
 497     struct inpcbinfo *pcbinfo)
 498 {
 499         struct udphdr uh;
 500         struct ip6_hdr *ip6;
 501         struct mbuf *m;
 502         int off = 0;
 503         struct ip6ctlparam *ip6cp = NULL;
 504         const struct sockaddr_in6 *sa6_src = NULL;
 505         void *cmdarg;
 506         struct inpcb *(*notify)(struct inpcb *, int) = udp_notify;
 507         struct udp_portonly {
 508                 u_int16_t uh_sport;
 509                 u_int16_t uh_dport;
 510         } *uhp;
 511
 512         if (sa->sa_family != AF_INET6 ||
 513             sa->sa_len != sizeof(struct sockaddr_in6))
 514                 return;
 515
 516         if ((unsigned)cmd >= PRC_NCMDS)
 517                 return;
 518         if (PRC_IS_REDIRECT(cmd))
 519                 notify = in6_rtchange, d = NULL;
 520         else if (cmd == PRC_HOSTDEAD)
 521                 d = NULL;
 522         else if (inet6ctlerrmap[cmd] == 0)
 523                 return;
 524
 525         /* if the parameter is from icmp6, decode it. */
 526         if (d != NULL) {
 527                 ip6cp = (struct ip6ctlparam *)d;
 528                 m = ip6cp->ip6c_m;
 529                 ip6 = ip6cp->ip6c_ip6;
 530                 off = ip6cp->ip6c_off;
 531                 cmdarg = ip6cp->ip6c_cmdarg;
 532                 sa6_src = ip6cp->ip6c_src;
 533         } else {
 534                 m = NULL;
 535                 ip6 = NULL;
 536                 cmdarg = NULL;
 537                 sa6_src = &sa6_any;
 538         }
 539
 540         if (ip6) {
 541                 /*
 542                  * XXX: We assume that when IPV6 is non NULL,
 543                  * M and OFF are valid.
 544                  */
 545
 546                 /* Check if we can safely examine src and dst ports. */
 547                 if (m->m_pkthdr.len < off + sizeof(*uhp))
 548                         return;
 549
 550                 bzero(&uh, sizeof(uh));
 551                 m_copydata(m, off, sizeof(*uhp), (caddr_t)&uh);
 552
 553                 (void)in6_pcbnotify(pcbinfo, sa, uh.uh_dport,
 554                     (struct sockaddr *)ip6cp->ip6c_src, uh.uh_sport, cmd,
 555                     cmdarg, notify);
 556         } else
 557                 (void)in6_pcbnotify(pcbinfo, sa, 0,
 558                     (const struct sockaddr *)sa6_src, 0, cmd, cmdarg, notify);
 559 }
 560
 561 void
 562 udp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 563 {
 564
 565         return (udp6_common_ctlinput(cmd, sa, d, &V_udbinfo));
 566 }
 567
 568 void
 569 udplite6_ctlinput(int cmd, struct sockaddr *sa, void *d)
 570 {
 571
 572         return (udp6_common_ctlinput(cmd, sa, d, &V_ulitecbinfo));
 573 }
 574
 575 static int
 576 udp6_getcred(SYSCTL_HANDLER_ARGS)
 577 {
 578         struct xucred xuc;
 579         struct sockaddr_in6 addrs[2];
 580         struct inpcb *inp;
 581         int error;
 582
 583         error = priv_check(req->td, PRIV_NETINET_GETCRED);
 584         if (error)
 585                 return (error);
 586
 587         if (req->newlen != sizeof(addrs))
 588                 return (EINVAL);
 589         if (req->oldlen != sizeof(struct xucred))
 590                 return (EINVAL);
 591         error = SYSCTL_IN(req, addrs, sizeof(addrs));
 592         if (error)
 593                 return (error);
 594         if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
 595             (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
 596                 return (error);
 597         }
 598         inp = in6_pcblookup(&V_udbinfo, &addrs[1].sin6_addr,
 599             addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port,
 600             INPLOOKUP_WILDCARD | INPLOOKUP_RLOCKPCB, NULL);
 601         if (inp != NULL) {
 602                 INP_RLOCK_ASSERT(inp);
 603                 if (inp->inp_socket == NULL)
 604                         error = ENOENT;
 605                 if (error == 0)
 606                         error = cr_canseesocket(req->td->td_ucred,
 607                             inp->inp_socket);
 608                 if (error == 0)
 609                         cru2x(inp->inp_cred, &xuc);
 610                 INP_RUNLOCK(inp);
 611         } else
 612                 error = ENOENT;
 613         if (error == 0)
 614                 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
 615         return (error);
 616 }
 617
 618 SYSCTL_PROC(_net_inet6_udp6, OID_AUTO, getcred, CTLTYPE_OPAQUE|CTLFLAG_RW, 0,
 619     0, udp6_getcred, "S,xucred", "Get the xucred of a UDP6 connection");
 620
 621 static int
 622 udp6_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr6,
 623     struct mbuf *control, struct thread *td)
 624 {
 625         u_int32_t ulen = m->m_pkthdr.len;
 626         u_int32_t plen = sizeof(struct udphdr) + ulen;
 627         struct ip6_hdr *ip6;
 628         struct udphdr *udp6;
 629         struct in6_addr *laddr, *faddr, in6a;
 630         struct sockaddr_in6 *sin6 = NULL;
 631         struct ifnet *oifp = NULL;
 632         int cscov_partial = 0;
 633         int scope_ambiguous = 0;
 634         u_short fport;
 635         int error = 0;
 636         uint8_t nxt;
 637         uint16_t cscov = 0;
 638         struct ip6_pktopts *optp, opt;
 639         int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
 640         int flags;
 641         struct sockaddr_in6 tmp;
 642
 643         INP_WLOCK_ASSERT(inp);
 644         INP_HASH_WLOCK_ASSERT(inp->inp_pcbinfo);
 645
 646         if (addr6) {
 647                 /* addr6 has been validated in udp6_send(). */
 648                 sin6 = (struct sockaddr_in6 *)addr6;
 649
 650                 /* protect *sin6 from overwrites */
 651                 tmp = *sin6;
 652                 sin6 = &tmp;
 653
 654                 /*
 655                  * Application should provide a proper zone ID or the use of
 656                  * default zone IDs should be enabled.  Unfortunately, some
 657                  * applications do not behave as it should, so we need a
 658                  * workaround.  Even if an appropriate ID is not determined,
 659                  * we'll see if we can determine the outgoing interface.  If we
 660                  * can, determine the zone ID based on the interface below.
 661                  */
 662                 if (sin6->sin6_scope_id == 0 && !V_ip6_use_defzone)
 663                         scope_ambiguous = 1;
 664                 if ((error = sa6_embedscope(sin6, V_ip6_use_defzone)) != 0)
 665                         return (error);
 666         }
 667
 668         if (control) {
 669                 if ((error = ip6_setpktopts(control, &opt,
 670                     inp->in6p_outputopts, td->td_ucred, IPPROTO_UDP)) != 0)
 671                         goto release;
 672                 optp = &opt;
 673         } else
 674                 optp = inp->in6p_outputopts;
 675
 676         if (sin6) {
 677                 faddr = &sin6->sin6_addr;
 678
 679                 /*
 680                  * Since we saw no essential reason for calling in_pcbconnect,
 681                  * we get rid of such kind of logic, and call in6_selectsrc
 682                  * and in6_pcbsetport in order to fill in the local address
 683                  * and the local port.
 684                  */
 685                 if (sin6->sin6_port == 0) {
 686                         error = EADDRNOTAVAIL;
 687                         goto release;
 688                 }
 689
 690                 if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 691                         /* how about ::ffff:0.0.0.0 case? */
 692                         error = EISCONN;
 693                         goto release;
 694                 }
 695
 696                 fport = sin6->sin6_port; /* allow 0 port */
 697
 698                 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
 699                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 700                                 /*
 701                                  * I believe we should explicitly discard the
 702                                  * packet when mapped addresses are disabled,
 703                                  * rather than send the packet as an IPv6 one.
 704                                  * If we chose the latter approach, the packet
 705                                  * might be sent out on the wire based on the
 706                                  * default route, the situation which we'd
 707                                  * probably want to avoid.
 708                                  * (20010421 jinmei@kame.net)
 709                                  */
 710                                 error = EINVAL;
 711                                 goto release;
 712                         }
 713                         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
 714                             !IN6_IS_ADDR_V4MAPPED(&inp->in6p_laddr)) {
 715                                 /*
 716                                  * when remote addr is an IPv4-mapped address,
 717                                  * local addr should not be an IPv6 address,
 718                                  * since you cannot determine how to map IPv6
 719                                  * source address to IPv4.
 720                                  */
 721                                 error = EINVAL;
 722                                 goto release;
 723                         }
 724
 725                         af = AF_INET;
 726                 }
 727
 728                 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
 729                         error = in6_selectsrc(sin6, optp, inp, NULL,
 730                             td->td_ucred, &oifp, &in6a);
 731                         if (error)
 732                                 goto release;
 733                         if (oifp && scope_ambiguous &&
 734                             (error = in6_setscope(&sin6->sin6_addr,
 735                             oifp, NULL))) {
 736                                 goto release;
 737                         }
 738                         laddr = &in6a;
 739                 } else
 740                         laddr = &inp->in6p_laddr;       /* XXX */
 741                 if (laddr == NULL) {
 742                         if (error == 0)
 743                                 error = EADDRNOTAVAIL;
 744                         goto release;
 745                 }
 746                 if (inp->inp_lport == 0 &&
 747                     (error = in6_pcbsetport(laddr, inp, td->td_ucred)) != 0) {
 748                         /* Undo an address bind that may have occurred. */
 749                         inp->in6p_laddr = in6addr_any;
 750                         goto release;
 751                 }
 752         } else {
 753                 if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 754                         error = ENOTCONN;
 755                         goto release;
 756                 }
 757                 if (IN6_IS_ADDR_V4MAPPED(&inp->in6p_faddr)) {
 758                         if ((inp->inp_flags & IN6P_IPV6_V6ONLY)) {
 759                                 /*
 760                                  * XXX: this case would happen when the
 761                                  * application sets the V6ONLY flag after
 762                                  * connecting the foreign address.
 763                                  * Such applications should be fixed,
 764                                  * so we bark here.
 765                                  */
 766                                 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
 767                                     "option was set for a connected socket\n");
 768                                 error = EINVAL;
 769                                 goto release;
 770                         } else
 771                                 af = AF_INET;
 772                 }
 773                 laddr = &inp->in6p_laddr;
 774                 faddr = &inp->in6p_faddr;
 775                 fport = inp->inp_fport;
 776         }
 777
 778         if (af == AF_INET)
 779                 hlen = sizeof(struct ip);
 780
 781         /*
 782          * Calculate data length and get a mbuf
 783          * for UDP and IP6 headers.
 784          */
 785         M_PREPEND(m, hlen + sizeof(struct udphdr), M_NOWAIT);
 786         if (m == 0) {
 787                 error = ENOBUFS;
 788                 goto release;
 789         }
 790
 791         /*
 792          * Stuff checksum and output datagram.
 793          */
 794         nxt = (inp->inp_socket->so_proto->pr_protocol == IPPROTO_UDP) ?
 795             IPPROTO_UDP : IPPROTO_UDPLITE;
 796         udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
 797         udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
 798         udp6->uh_dport = fport;
 799         if (nxt == IPPROTO_UDPLITE) {
 800                 struct udpcb *up;
 801
 802                 up = intoudpcb(inp);
 803                 cscov = up->u_txcslen;
 804                 if (cscov >= plen)
 805                         cscov = 0;
 806                 udp6->uh_ulen = htons(cscov);
 807                 /*
 808                  * For UDP-Lite, checksum coverage length of zero means
 809                  * the entire UDPLite packet is covered by the checksum.
 810                  */
 811                 cscov_partial = (cscov == 0) ? 0 : 1;
 812         } else if (plen <= 0xffff)
 813                 udp6->uh_ulen = htons((u_short)plen);
 814         else
 815                 udp6->uh_ulen = 0;
 816         udp6->uh_sum = 0;
 817
 818         switch (af) {
 819         case AF_INET6:
 820                 ip6 = mtod(m, struct ip6_hdr *);
 821                 ip6->ip6_flow   = inp->inp_flow & IPV6_FLOWINFO_MASK;
 822                 ip6->ip6_vfc    &= ~IPV6_VERSION_MASK;
 823                 ip6->ip6_vfc    |= IPV6_VERSION;
 824                 ip6->ip6_plen   = htons((u_short)plen);
 825                 ip6->ip6_nxt    = nxt;
 826                 ip6->ip6_hlim   = in6_selecthlim(inp, NULL);
 827                 ip6->ip6_src    = *laddr;
 828                 ip6->ip6_dst    = *faddr;
 829
 830                 if (cscov_partial) {
 831                         if ((udp6->uh_sum = in6_cksum_partial(m, nxt,
 832                             sizeof(struct ip6_hdr), plen, cscov)) == 0)
 833                                 udp6->uh_sum = 0xffff;
 834                 } else {
 835                         udp6->uh_sum = in6_cksum_pseudo(ip6, plen, nxt, 0);
 836                         m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
 837                         m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
 838                 }
 839
 840                 flags = 0;
 841
 842                 UDP_PROBE(send, NULL, inp, ip6, inp, udp6);
 843                 UDPSTAT_INC(udps_opackets);
 844                 error = ip6_output(m, optp, NULL, flags, inp->in6p_moptions,
 845                     NULL, inp);
 846                 break;
 847         case AF_INET:
 848                 error = EAFNOSUPPORT;
 849                 goto release;
 850         }
 851         goto releaseopt;
 852
 853 release:
 854         m_freem(m);
 855
 856 releaseopt:
 857         if (control) {
 858                 ip6_clearpktopts(&opt, -1);
 859                 m_freem(control);
 860         }
 861         return (error);
 862 }
 863
 864 static void
 865 udp6_abort(struct socket *so)
 866 {
 867         struct inpcb *inp;
 868         struct inpcbinfo *pcbinfo;
 869
 870         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 871         inp = sotoinpcb(so);
 872         KASSERT(inp != NULL, ("udp6_abort: inp == NULL"));
 873
 874 #ifdef INET
 875         if (inp->inp_vflag & INP_IPV4) {
 876                 struct pr_usrreqs *pru;
 877
 878                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
 879                 (*pru->pru_abort)(so);
 880                 return;
 881         }
 882 #endif
 883
 884         INP_WLOCK(inp);
 885         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
 886                 INP_HASH_WLOCK(pcbinfo);
 887                 in6_pcbdisconnect(inp);
 888                 inp->in6p_laddr = in6addr_any;
 889                 INP_HASH_WUNLOCK(pcbinfo);
 890                 soisdisconnected(so);
 891         }
 892         INP_WUNLOCK(inp);
 893 }
 894
 895 static int
 896 udp6_attach(struct socket *so, int proto, struct thread *td)
 897 {
 898         struct inpcb *inp;
 899         struct inpcbinfo *pcbinfo;
 900         int error;
 901
 902         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 903         inp = sotoinpcb(so);
 904         KASSERT(inp == NULL, ("udp6_attach: inp != NULL"));
 905
 906         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 907                 error = soreserve(so, udp_sendspace, udp_recvspace);
 908                 if (error)
 909                         return (error);
 910         }
 911         INP_INFO_WLOCK(pcbinfo);
 912         error = in_pcballoc(so, pcbinfo);
 913         if (error) {
 914                 INP_INFO_WUNLOCK(pcbinfo);
 915                 return (error);
 916         }
 917         inp = (struct inpcb *)so->so_pcb;
 918         inp->inp_vflag |= INP_IPV6;
 919         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
 920                 inp->inp_vflag |= INP_IPV4;
 921         inp->in6p_hops = -1;    /* use kernel default */
 922         inp->in6p_cksum = -1;   /* just to be sure */
 923         /*
 924          * XXX: ugly!!
 925          * IPv4 TTL initialization is necessary for an IPv6 socket as well,
 926          * because the socket may be bound to an IPv6 wildcard address,
 927          * which may match an IPv4-mapped IPv6 address.
 928          */
 929         inp->inp_ip_ttl = V_ip_defttl;
 930
 931         error = udp_newudpcb(inp);
 932         if (error) {
 933                 in_pcbdetach(inp);
 934                 in_pcbfree(inp);
 935                 INP_INFO_WUNLOCK(pcbinfo);
 936                 return (error);
 937         }
 938         INP_WUNLOCK(inp);
 939         INP_INFO_WUNLOCK(pcbinfo);
 940         return (0);
 941 }
 942
 943 static int
 944 udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 945 {
 946         struct inpcb *inp;
 947         struct inpcbinfo *pcbinfo;
 948         int error;
 949
 950         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 951         inp = sotoinpcb(so);
 952         KASSERT(inp != NULL, ("udp6_bind: inp == NULL"));
 953
 954         INP_WLOCK(inp);
 955         INP_HASH_WLOCK(pcbinfo);
 956         inp->inp_vflag &= ~INP_IPV4;
 957         inp->inp_vflag |= INP_IPV6;
 958         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
 959                 struct sockaddr_in6 *sin6_p;
 960
 961                 sin6_p = (struct sockaddr_in6 *)nam;
 962
 963                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6_p->sin6_addr))
 964                         inp->inp_vflag |= INP_IPV4;
 965 #ifdef INET
 966                 else if (IN6_IS_ADDR_V4MAPPED(&sin6_p->sin6_addr)) {
 967                         struct sockaddr_in sin;
 968
 969                         in6_sin6_2_sin(&sin, sin6_p);
 970                         inp->inp_vflag |= INP_IPV4;
 971                         inp->inp_vflag &= ~INP_IPV6;
 972                         error = in_pcbbind(inp, (struct sockaddr *)&sin,
 973                             td->td_ucred);
 974                         goto out;
 975                 }
 976 #endif
 977         }
 978
 979         error = in6_pcbbind(inp, nam, td->td_ucred);
 980 #ifdef INET
 981 out:
 982 #endif
 983         INP_HASH_WUNLOCK(pcbinfo);
 984         INP_WUNLOCK(inp);
 985         return (error);
 986 }
 987
 988 static void
 989 udp6_close(struct socket *so)
 990 {
 991         struct inpcb *inp;
 992         struct inpcbinfo *pcbinfo;
 993
 994         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
 995         inp = sotoinpcb(so);
 996         KASSERT(inp != NULL, ("udp6_close: inp == NULL"));
 997
 998 #ifdef INET
 999         if (inp->inp_vflag & INP_IPV4) {
1000                 struct pr_usrreqs *pru;
1001
1002                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1003                 (*pru->pru_disconnect)(so);
1004                 return;
1005         }
1006 #endif
1007         INP_WLOCK(inp);
1008         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1009                 INP_HASH_WLOCK(pcbinfo);
1010                 in6_pcbdisconnect(inp);
1011                 inp->in6p_laddr = in6addr_any;
1012                 INP_HASH_WUNLOCK(pcbinfo);
1013                 soisdisconnected(so);
1014         }
1015         INP_WUNLOCK(inp);
1016 }
1017
1018 static int
1019 udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1020 {
1021         struct inpcb *inp;
1022         struct inpcbinfo *pcbinfo;
1023         struct sockaddr_in6 *sin6;
1024         int error;
1025
1026         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1027         inp = sotoinpcb(so);
1028         sin6 = (struct sockaddr_in6 *)nam;
1029         KASSERT(inp != NULL, ("udp6_connect: inp == NULL"));
1030
1031         /*
1032          * XXXRW: Need to clarify locking of v4/v6 flags.
1033          */
1034         INP_WLOCK(inp);
1035 #ifdef INET
1036         if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
1037                 struct sockaddr_in sin;
1038
1039                 if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
1040                         error = EINVAL;
1041                         goto out;
1042                 }
1043                 if (inp->inp_faddr.s_addr != INADDR_ANY) {
1044                         error = EISCONN;
1045                         goto out;
1046                 }
1047                 in6_sin6_2_sin(&sin, sin6);
1048                 inp->inp_vflag |= INP_IPV4;
1049                 inp->inp_vflag &= ~INP_IPV6;
1050                 error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
1051                 if (error != 0)
1052                         goto out;
1053                 INP_HASH_WLOCK(pcbinfo);
1054                 error = in_pcbconnect(inp, (struct sockaddr *)&sin,
1055                     td->td_ucred);
1056                 INP_HASH_WUNLOCK(pcbinfo);
1057                 if (error == 0)
1058                         soisconnected(so);
1059                 goto out;
1060         }
1061 #endif
1062         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1063                 error = EISCONN;
1064                 goto out;
1065         }
1066         inp->inp_vflag &= ~INP_IPV4;
1067         inp->inp_vflag |= INP_IPV6;
1068         error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
1069         if (error != 0)
1070                 goto out;
1071         INP_HASH_WLOCK(pcbinfo);
1072         error = in6_pcbconnect(inp, nam, td->td_ucred);
1073         INP_HASH_WUNLOCK(pcbinfo);
1074         if (error == 0)
1075                 soisconnected(so);
1076 out:
1077         INP_WUNLOCK(inp);
1078         return (error);
1079 }
1080
1081 static void
1082 udp6_detach(struct socket *so)
1083 {
1084         struct inpcb *inp;
1085         struct inpcbinfo *pcbinfo;
1086         struct udpcb *up;
1087
1088         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1089         inp = sotoinpcb(so);
1090         KASSERT(inp != NULL, ("udp6_detach: inp == NULL"));
1091
1092         INP_INFO_WLOCK(pcbinfo);
1093         INP_WLOCK(inp);
1094         up = intoudpcb(inp);
1095         KASSERT(up != NULL, ("%s: up == NULL", __func__));
1096         in_pcbdetach(inp);
1097         in_pcbfree(inp);
1098         INP_INFO_WUNLOCK(pcbinfo);
1099         udp_discardcb(up);
1100 }
1101
1102 static int
1103 udp6_disconnect(struct socket *so)
1104 {
1105         struct inpcb *inp;
1106         struct inpcbinfo *pcbinfo;
1107         int error;
1108
1109         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1110         inp = sotoinpcb(so);
1111         KASSERT(inp != NULL, ("udp6_disconnect: inp == NULL"));
1112
1113 #ifdef INET
1114         if (inp->inp_vflag & INP_IPV4) {
1115                 struct pr_usrreqs *pru;
1116
1117                 pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1118                 (void)(*pru->pru_disconnect)(so);
1119                 return (0);
1120         }
1121 #endif
1122
1123         INP_WLOCK(inp);
1124
1125         if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr)) {
1126                 error = ENOTCONN;
1127                 goto out;
1128         }
1129
1130         INP_HASH_WLOCK(pcbinfo);
1131         in6_pcbdisconnect(inp);
1132         inp->in6p_laddr = in6addr_any;
1133         INP_HASH_WUNLOCK(pcbinfo);
1134         SOCK_LOCK(so);
1135         so->so_state &= ~SS_ISCONNECTED;                /* XXX */
1136         SOCK_UNLOCK(so);
1137 out:
1138         INP_WUNLOCK(inp);
1139         return (0);
1140 }
1141
1142 static int
1143 udp6_send(struct socket *so, int flags, struct mbuf *m,
1144     struct sockaddr *addr, struct mbuf *control, struct thread *td)
1145 {
1146         struct inpcb *inp;
1147         struct inpcbinfo *pcbinfo;
1148         int error = 0;
1149
1150         pcbinfo = get_inpcbinfo(so->so_proto->pr_protocol);
1151         inp = sotoinpcb(so);
1152         KASSERT(inp != NULL, ("udp6_send: inp == NULL"));
1153
1154         INP_WLOCK(inp);
1155         if (addr) {
1156                 if (addr->sa_len != sizeof(struct sockaddr_in6)) {
1157                         error = EINVAL;
1158                         goto bad;
1159                 }
1160                 if (addr->sa_family != AF_INET6) {
1161                         error = EAFNOSUPPORT;
1162                         goto bad;
1163                 }
1164         }
1165
1166 #ifdef INET
1167         if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
1168                 int hasv4addr;
1169                 struct sockaddr_in6 *sin6 = 0;
1170
1171                 if (addr == 0)
1172                         hasv4addr = (inp->inp_vflag & INP_IPV4);
1173                 else {
1174                         sin6 = (struct sockaddr_in6 *)addr;
1175                         hasv4addr = IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)
1176                             ? 1 : 0;
1177                 }
1178                 if (hasv4addr) {
1179                         struct pr_usrreqs *pru;
1180
1181                         /*
1182                          * XXXRW: We release UDP-layer locks before calling
1183                          * udp_send() in order to avoid recursion.  However,
1184                          * this does mean there is a short window where inp's
1185                          * fields are unstable.  Could this lead to a
1186                          * potential race in which the factors causing us to
1187                          * select the UDPv4 output routine are invalidated?
1188                          */
1189                         INP_WUNLOCK(inp);
1190                         if (sin6)
1191                                 in6_sin6_2_sin_in_sock(addr);
1192                         pru = inetsw[ip_protox[IPPROTO_UDP]].pr_usrreqs;
1193                         /* addr will just be freed in sendit(). */
1194                         return ((*pru->pru_send)(so, flags, m, addr, control,
1195                             td));
1196                 }
1197         }
1198 #endif
1199 #ifdef MAC
1200         mac_inpcb_create_mbuf(inp, m);
1201 #endif
1202         INP_HASH_WLOCK(pcbinfo);
1203         error = udp6_output(inp, m, addr, control, td);
1204         INP_HASH_WUNLOCK(pcbinfo);
1205 #ifdef INET
1206 #endif
1207         INP_WUNLOCK(inp);
1208         return (error);
1209
1210 bad:
1211         INP_WUNLOCK(inp);
1212         m_freem(m);
1213         return (error);
1214 }
1215
1216 struct pr_usrreqs udp6_usrreqs = {
1217         .pru_abort =            udp6_abort,
1218         .pru_attach =           udp6_attach,
1219         .pru_bind =             udp6_bind,
1220         .pru_connect =          udp6_connect,
1221         .pru_control =          in6_control,
1222         .pru_detach =           udp6_detach,
1223         .pru_disconnect =       udp6_disconnect,
1224         .pru_peeraddr =         in6_mapped_peeraddr,
1225         .pru_send =             udp6_send,
1226         .pru_shutdown =         udp_shutdown,
1227         .pru_sockaddr =         in6_mapped_sockaddr,
1228         .pru_soreceive =        soreceive_dgram,
1229         .pru_sosend =           sosend_dgram,
1230         .pru_sosetlabel =       in_pcbsosetlabel,
1231         .pru_close =            udp6_close
1232 };